Page 17 - Reconstructive Techniques in Musculoskeletal Tumor Surgery

The most common primary tumor of the pelvic bones in adults is 1 chondrosarcoma38. Pelvic chondrosarcomas are notorious for the high risk of (late) recurrence48. However, speci c studies on this tumor type are lacking. Most previous
studies focused on outcomes of resection and reconstructive techniques rather
than on oncological outcome. However, to choose the optimal treatment and reconstructive technique, and to reduce the rate of unnecessary reoperations, it is important to identify patients with a poor prognosis in an early stage49. In chapter 2, we present a multicenter study on primary central chondrosarcoma of the pelvis. With this study, we aimed to gain insight in the outcome of treatment of this speci c type of tumor, and to identify risk factors for impaired oncological outcome.
Following a type 2 internal hemipelvectomy, reconstruction can be achieved with metallic implants, biological transplants, or with techniques that utilize a combination of the two. Reconstructions with metallic implants include transposition of the center of the hip joint50 and various types of endoprosthetic reconstructions41, 51, 52. Biological techniques include iliofemoral arthrodesis or pseudarthrosis53, pelvic allografts54, irradiated autografts (i.e., the resection specimen is irradiated and re-implanted)55 and allograft-prosthetic composites56. Disadvantages of biological techniques include limited functional outcomes and a considerable risk of infection, nonunion, fracture, and graft resorption50, 54-58.
The majority of surgeons focused on the use of endoprosthetic (metallic) implants during the last decades. Most of the implants that have been used had originally been developed for reconstruction of large acetabular defects in extended revision hip arthroplasty41, 51. The saddle prosthesis (Link, Hamburg, Germany), which was introduced in 1979, was the rst implant to be used for pelvic reconstruction in musculoskeletal oncology on a regular basis38, 51, 59, 60. Although favorable short-term results have been published38, 61, long-term clinical outcome and functional results were disappointing51. Apart from high rates of infection and implant breakage, saddle prostheses were associated with a substantial risk of cranial migration51, 62.
In the quest for a successful implant for pelvic reconstruction, many designers have come up with a stemmed acetabular device. These often show similarities to the Ring prosthesis, which was introduced in 1968. He presented a device that consisted of a cup with a long, threaded stem, designed for reconstruction of acetabular defects63 ( gure 7). Ring described that “weight is transferred from the sacrum to the articular facet of the ilium, and thence through a thick bar of bone which extends down to the upper part of the acetabulum”.
General introduction
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